JP2006335969A - Water absorption-preventing material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an emulsion type water absorption-preventing material excellent in permeability into civil engineering or architectural materials such as concrete, developing good water repellency comparable with a solvent type permeable water absorption-preventing material, and suppressing the occurrence of stains and mold over a long period of time. <P>SOLUTION: This water absorption-preventing material comprises an organosilicon compound emulsion and a water-soluble water-repellent. Preferably the organosilicon compound emulsion is an emulsion containing an alkylalkoxysilane and an alkylalkoxysiloxane, and the water-soluble water-repellent is a composition containing a fluoroalkyl group-containing organopolysiloxane. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a water absorption preventing material for civil engineering and building materials.

  Conventionally, it is widely known that alkylalkoxysilanes and their condensates are useful as permeable water absorption preventing materials for civil engineering and building materials such as concrete. Since the permeable water absorption preventive material penetrates into concrete or the like and forms a thick water-repellent layer on the surface layer portion, the water absorption preventive performance is maintained for a long period of time, and various deterioration phenomena due to the penetration of salt and moisture can be suppressed. In general, a material obtained by diluting these alkylalkoxysilanes with various solvents is used as the permeable water absorption preventing material. However, when these solvent-type water absorption preventing materials are applied to civil engineering and building materials, they exhibit high water repellency, but their use is limited due to the volatility and flammability of the solvent. For example, when isopropyl alcohol is used as a solvent, there is a problem that the solvent is rapidly evaporated and the water absorption preventing material does not sufficiently penetrate into the base material, resulting in poor durability of the coated product. On the other hand, when a solvent that does not easily volatilize is used, there are problems that the coated surface becomes wet and difficult to dry, and overcoating cannot be performed. In general, the solvent type has a problem that it cannot be applied to a wet concrete surface.

In order to solve these problems, water-based water absorption preventive materials have attracted attention in recent years. As water-based water absorption preventing materials, emulsions of alkylalkoxysilanes are known (see Patent Document 1). However, this emulsion is composed of a small hydrolyzable silane having a molecular weight of 500 or less and easily separates layers, so that it is necessary to use a large amount of an emulsifier having an HLB value of 4 to 15. There is a problem that the emulsifier remains on the surface of the base material after the emulsion containing a large amount of the emulsifier is applied to the base material and dried, and the water repellency of the base material application surface is extremely deteriorated. On the other hand, in order to improve water repellency, a composition in which an alkylalkoxysilane emulsion and a zirconium-based emulsion or a fluoroemulsion of a perfluoroalkyl group-containing acrylic resin are mixed as a water repellent is also known (see Patent Document 2). ). However, zirconium-based emulsions and fluorine-based emulsions are affected by the emulsifier contained therein, and the water repellency thereof is not as high as that of the solvent-type water absorption preventing material, and there are problems such as adhesion of dirt and wrinkles on the coated surface.
Japanese Patent Laid-Open No. 62-197369 Japanese Patent Laid-Open No. 6-172777

  An object of the present invention is an emulsion that has excellent permeability to civil engineering and building materials such as concrete and exhibits good water repellency comparable to solvent-type permeable water-absorbing preventing materials, and suppresses the generation of dirt and wrinkles over a long period of time. The object is to provide a mold water absorption prevention material.

The present invention provides a water absorption preventing material as shown below.
Item 1. A water absorption preventing material comprising an organic silicon compound emulsion and a water-soluble water repellent.
Item 2. The organosilicon compound emulsion is an emulsion containing (a) an alkylalkoxysilane and (b) an alkylalkoxysiloxane, wherein the ratio of (a) and (b) is 1: 0.05 to 0.4 by weight, and Item 2. The water absorption preventing material according to Item 1, wherein the total amount of (a) and (b) is 1 to 80% by weight of the total amount of the emulsion.
Item 3. Item 3. The water absorption preventing material according to Item 1 or 2, wherein the water-soluble water repellent is a composition containing a fluoroalkyl group-containing organopolysiloxane.
Item 4. Item 4. The water absorption preventing material according to any one of Items 1 to 3, wherein the water-soluble water repellent is 0.01 to 30% by weight based on the total amount of the organosilicon compound emulsion.

  Hereinafter, the present invention will be described in detail.

  The water absorption preventing material of the present invention is an emulsion type water absorption preventing material containing an organic silicon compound emulsion and a water-soluble water repellent.

  Although it does not specifically limit as an organosilicon compound emulsion used in this invention, The emulsion containing an alkyl alkoxysilane and alkyl alkoxysiloxane is used suitably.

  Examples of the alkylalkoxysilane include methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltrimethoxysilane. Ethoxysilane, pentyltrimethoxysilane, pentyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, nonyltrimethoxysilane, nonyltri Ethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, undecyltrimethoxysilane, undecyltriethoxysilane , Dodecyltrimethoxysilane, dodecyltriethoxysilane, tridecyltrimethoxysilane, tridecyltriethoxysilane, tetradecyltrimethoxysilane, tetradecyltriethoxysilane, pentadecyltrimethoxysilane, pentadecyltriethoxysilane, hexadecyltri Examples include methoxysilane, hexadecyltriethoxysilane, heptadecyltrimethoxysilane, heptadecyltriethoxysilane, octadecyltrimethoxysilane, and octadecyltriethoxysilane. Of these, hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, and decyltrimethoxysilane are preferably used.

  The alkylalkoxysiloxane is usually a mixture of various alkylalkoxysiloxanes obtained by hydrolyzing and polycondensation of one kind of alkylalkoxysilane alone or a mixture of two or more kinds in water. As such alkylalkoxysiloxanes, those commercially available under the trade name “TSR165” of GE Toshiba Silicone Co., Ltd. and the trade name “SILRES MSE100” of Asahi Kasei Wacker Silicone Co., Ltd. can be used.

  The ratio of the alkylalkoxysilane and the alkylalkoxysiloxane in the organosilicon compound emulsion is preferably 1: 0.05 to 0.4, more preferably 1: 0.07 to 0.3, by weight. 1: 0.1 to 0.25 is particularly preferable. When the weight ratio of the alkylalkoxysiloxane is less than 0.05, phase separation of the obtained water-based emulsion type water-absorption preventing material may easily occur. Moreover, when the weight ratio of alkyl alkoxysiloxane exceeds 0.4, there is a possibility that the permeability of the resulting water absorption preventing material to the base material may be deteriorated.

  The total amount of alkylalkoxysilane and alkylalkoxysiloxane is preferably 1 to 80% by weight, and more preferably 5 to 70% by weight, based on the total amount of the organosilicon compound emulsion. When the total amount of alkylalkoxysilane and alkylalkoxysiloxane is less than 1% by weight, a sufficient penetration depth cannot be obtained even if the obtained water absorption preventing material is applied to the base material, and the water absorption preventing property is maintained over a long period of time. There is a risk that it cannot be maintained. Moreover, when the total amount of alkyl alkoxysilane and alkyl alkoxy siloxane exceeds 80 weight%, the produced | generated emulsion may become unstable and may cause phase separation.

  The organosilicon compound emulsion can be obtained by mixing water and an emulsifier with the above alkylalkoxysilane and alkylalkoxysiloxane, and stirring and emulsifying at high speed using a stirring device such as a homomixer. There is no restriction | limiting in particular as an emulsifier used here, An anionic emulsifier, a nonionic emulsifier, and a cationic emulsifier can be used.

  Anionic emulsifiers include, for example, fatty acid salts, alkyl sulfate esters, alkylbenzene sulfonates, alkyl naphthalene sulfonates, alkyl sulfosuccinates, alkyl diphenyl ether disulfonates, alkyl phosphates, polyoxyethylene alkyls or alkyl allyls. Examples thereof include sulfate ester salts, naphthalene sulfonic acid formalin condensates, polyoxyethylene alkyl phosphate esters, and the like.

  Nonionic emulsifiers include, for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, oxyethylene oxypropylene block copolymer, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid ester, Examples include polyoxyethylene fatty acid esters and polyoxyethylene alkylamines.

  Examples of the cationic emulsifier include alkylamine salts, quaternary ammonium salts, alkylbetaines, and amine oxides.

  The emulsifier can be arbitrarily mixed as required, but in order not to reduce the water repellency after coating, the total amount of the emulsifier is 0.01% by weight to 10% by weight with respect to the alkylalkoxysilane component. Preferably there is. If the amount of emulsifier is too small, emulsification may be difficult. If the amount of emulsifier is too large, water repellency may not be exhibited.

  The present invention has the greatest feature in that a water-soluble water repellent is used.

  In general, a water repellent is defined as a substance that forms a hydrophobic film on the surface without changing the internal structure of the substrate and prevents water permeation. It is insoluble in water, dissolved in an organic solvent, or uses an emulsifier. Many of these are emulsified and dispersed in water. When these water repellents are added to the organosilicon compound emulsion, the organic solvent-soluble type water repellent affects the stability of the emulsion. As the emulsifying / dispersing type water repellent, an emulsion of a fluororesin mainly composed of a copolymer or mixture of an olefin or acrylic and a fluorine compound, or an emulsion of a compound having a fluoroalkyl group is used. There is no effect on the stability of the silicon compound emulsion. However, in the emulsion of fluororesin, it is easy to form a thick coating film and has good water resistance. However, when applied to a mortar substrate, for example, the water repellency is low due to the influence of copolymerized or mixed olefin and acrylic. (Water contact angle is about 90 °). On the other hand, an emulsion of a compound having a fluoroalkyl group does not form a thick coating film, but requires a large amount of emulsifier for emulsification, and therefore exhibits only a water repellency of about 125 ° in water contact angle due to the effect of the emulsifier contained. .

  In contrast, the water-soluble water repellent used in the present invention completely dissolves in water, forms a thin film after being applied to a substrate and dried, does not contain olefins or acrylics, and contains an emulsifier. Therefore, the water contact angle shows a high water repellency of 130 ° or more. In addition, the water-soluble water repellent does not impair the stability of the emulsion relative to the organosilicon compound emulsion, and the water repellency is further improved by the interaction with the water repellent layer formed by the organosilicon compound emulsion.

  Such a water-soluble water repellent is not particularly limited as long as it dissolves in water, forms a thin film after being applied to a substrate and dried, and exhibits a water repellent effect. For example, there are a composition containing an alkylalkoxysiliconate and a fluoroalkyl group-containing organopolysiloxane, and a composition containing a fluoroalkyl group-containing organopolysiloxane is preferably used. Such a composition containing a fluoroalkyl group-containing organopolysiloxane can be obtained, for example, by adding an acid to a dealcoholized or dehydrated condensate of aminoalkylalkoxysilane and fluoroalkylalkoxysilane. As more specific synthesis examples, methods described in JP-A-10-158520 and JP-A-2002-194336 can be used. In addition, when the said water-soluble water repellent is apply | coated to a base material independently, water repellency will express, but it does not osmose | permeate the inside of a base material, durability is inferior and it exhibits a wet color.

  The blending ratio of the water-soluble water repellent is preferably from 0.01 to 30% by weight, more preferably from 0.02 to 25% by weight, based on the total amount of the organic silicon compound emulsion. If it is less than 0.01% by weight, sufficient water repellency may not be obtained. If it exceeds 30% by weight, the appearance of the surface of concrete or the like exhibits a wet color and the hue may change.

  When the water-soluble water repellent is a composition containing a fluoroalkyl group-containing organopolysiloxane, the ratio of the alkylalkoxysilane and the fluoroalkyl group-containing organopolysiloxane in the water absorption preventing material is 1: 0. It is preferable that it is 0001-0.5, and it is more preferable that it is 1: 0.001-0.1.

  The water absorption preventing material of the present invention can be produced by adding and mixing a water-soluble water repellent to the organosilicon compound emulsion. Alternatively, it can also be produced by adding a water-soluble water repellent during the production of the organosilicon compound emulsion.

  The water absorption preventive material of the present invention may be diluted with water to adjust each active ingredient, or may be given a function by adding a water-soluble solvent such as alcohol, an antiseptic, an antifungal agent, a pH adjuster, or the like. it can.

  In order to apply the water absorption preventing material of the present invention to civil engineering / building materials, a roller, a brush, a spray or the like is used. Moreover, as a drying method, it may be left to dry at room temperature, or may be sun drying or heat drying.

  Civil engineering / building materials include, for example, porous civil engineering / building materials. More specifically, exposed concrete, lightweight concrete, precast concrete, lightweight foamed concrete (ALC), mortar, joint mortar, asbestos cement board, pulp cement board, Wood wool cement board, Cement-based extrusion board, Cement board with glass fiber (GRC), Cement board with carbon fiber, Calcium silicate board, Gypsum board, Hard board, Plaster, Plaster plaster, Dolomite plaster, Block, Brick, Tile, Examples thereof include materials mainly composed of inorganic materials such as roof tiles, natural stones, artificial stones, glass wool, rock wool and ceramic fibers, and materials mainly composed of organic materials such as wood, plywood and particle board.

  The water absorption preventive material of the present invention exhibits high water repellency equivalent to that of a solvent-type water absorption preventive material while being water-based, and has a long period of rainwater leakage due to severe wind and rain, material deterioration due to acid rain, contamination of soil, Can be prevented. When the water absorption preventing material of the present invention is applied to a base material, the water repellent layer formed inside the base material causes salt damage caused by seawater, frost damage in cold regions, white flower due to elution of salt in the base material, etc. Various problems caused by water can be solved.

  The water absorption preventive material of the present invention is excellent in permeability to civil engineering and building materials such as concrete and exhibits good water repellency comparable to solvent-type penetrable water absorption preventive materials. Can be suppressed.

  Hereinafter, the present invention will be described in more detail with reference to synthesis examples, examples and comparative examples of water-soluble water repellents, but the present invention is not limited to these examples.

Synthesis example 1
In a 250 ml reaction vessel equipped with a stirrer, 44.2 g of 3-aminopropyltriethoxysilane (trade name “TSL-8331” of GE Toshiba Silicone Co., Ltd.) and triethoxy-1,1,2,2-tridecafluorooctyl 93.4 g of silane was added, followed by 14.4 g of water and stirred for about 3 hours. After the completion of stirring, 9.2 g of formic acid was added to obtain a water-soluble water repellent. This water-soluble water repellent was miscible with water at any ratio.

Example 1
A mixture of 69 parts by weight of water and 1 part by weight of polyoxyethylene decyl ether (trade name “Neugen SD-400” from Daiichi Kogyo Seiyaku Co., Ltd.) was stirred at high speed with a homomixer, and then 27 parts by weight of hexyltriethoxysilane and Add 2 parts by weight of the water-soluble water repellent obtained in Synthesis Example 1 to the emulsion obtained by adding 3 parts by weight of alkyl alkoxysiloxane (trade name “TSR165” of GE Toshiba Silicone Co., Ltd.) and stirring at high speed with a homomixer. Partly added to obtain the water absorption preventing material of the present invention.

Example 2
The water absorption preventing material of the present invention was obtained by diluting the water absorption preventing material produced in Example 1 five times with water.

Example 3
The water absorption preventing material of the present invention was obtained by diluting the water absorption preventing material produced in Example 1 20 times with water.

Comparative Example 1
A mixture of 69 parts by weight of water and 1 part by weight of polyoxyethylene decyl ether (trade name “Neugen SD-400” from Daiichi Kogyo Seiyaku Co., Ltd.) was stirred at high speed with a homomixer, and then 27 parts by weight of hexyltriethoxysilane and 3 parts by weight of alkylalkoxysiloxane (trade name “TSR165” of GE Toshiba Silicone Co., Ltd.) was added and stirred at high speed with a homomixer to obtain a water absorption preventing material.

Comparative Example 2
A mixed solution of 48 parts by weight of water and 2 parts by weight of polyoxyethylene distyrenated phenyl ether (trade name “Neugen EA-20” of Daiichi Kogyo Seiyaku Co., Ltd.) was stirred at high speed with a homomixer, and then hexyltriethoxysilane 42 Fluorine-based aqueous emulsion water repellent (Asahi Glass Co., Ltd.) was added to the emulsion obtained by adding 8 parts by weight of alkylalkoxysiloxane (trade name “SILRES MSE100” of Asahi Kasei Wacker Silicone Co., Ltd.) and stirring at high speed with a homomixer. 4 parts by weight of a company name “Asahi Guard AG-740”) was added to obtain a water absorption preventing material.

Comparative Example 3
The water-soluble water repellent produced in Synthesis Example 1 was diluted 6.5 times with water to obtain a water absorption preventing material.

Comparative Example 4
The water-soluble water repellent produced in Synthesis Example 1 was diluted 500 times with water to obtain a water absorption preventing material.

  Various characteristics were evaluated by the following methods using the water absorption preventing materials obtained in Examples 1 to 3 and Comparative Examples 1 to 4.

[Evaluation methods]
(1) Storage stability 100 ml of the water absorption preventive material obtained in Examples and Comparative Examples is put in a 200 ml glass container and left at 40 ° C., and the state of phase separation of the emulsion after 6 months is visually observed. Observed. The results of phase separation after 6 months are shown in Table 1.

(2) Appearance, water repellency, penetration depth and water absorption ratio Mortar (70 mm x 70 mm x 20 mm) according to JIS R-5201 was used as a specimen, and water absorption prevention obtained in Examples and Comparative Examples was used for this. The material was applied to the entire surface at a rate of 200 g / m ² . In addition, the thing which does not apply | coat anything was made into the control | contrast. The obtained specimen was cured for several days in a constant temperature and humidity chamber at a temperature of 20 ° C. and a relative humidity of 65% RH, and then the coating appearance, water repellency (contact angle), penetration depth, and water absorption ratio were measured. Next, using a sunshine weather meter (trade name “Ducycle Sunshine Super Long Life Weather Meter WEL-SUN-DCH type” of Suga Test Instruments Co., Ltd.), black panel temperature 63 ° C., humidity 50%, rainfall conditions 60 minutes The accelerated weathering test was conducted under the test conditions of middle 12 minutes rainfall. The water repellency (contact angle) of the specimen after 250 hours was measured.

Appearance:
After applying the water absorption preventing material, the wet color state of the surface of the specimen cured for 7 days in a constant temperature and humidity chamber at a temperature of 20 ° C. and a relative humidity of 65% RH was compared with an uncoated substrate. The results are shown in Table 1.

Penetration depth:
After applying the water absorption preventive material, the test piece cured for 7 days in a constant temperature and humidity chamber at a temperature of 20 ° C. and a relative humidity of 65% RH is divided into two, and water is sprayed on the divided surface, so that water does not penetrate. The thickness of the part was measured. The results are shown in Table 1.

Water repellency (contact angle):
After applying a water absorption preventive material, the specimen was cured in a constant temperature and humidity chamber at a temperature of 20 ° C. and a relative humidity of 65% RH for 1, 3 and 7 days, and accelerated after being cured for 7 days in the constant temperature and humidity chamber. A water droplet having a diameter of 2 mm was placed on the specimen subjected to the weather resistance test, and the contact angle was measured with a contact angle measuring device (contact angle meter “S-150” manufactured by Kyowa Interface Science Co., Ltd.). The evaluation criteria were as follows. The results are shown in Table 1.
◎: Water droplet contact angle of 135 ° or more ○: Water droplet contact angle of less than 120 to 135 ° △: Water droplet contact angle of less than 80 to 120 ° ×: Immediate water absorption without forming water droplets Note that the contact angle is 135 ° or more In this case, it can be judged that the water repellency is very excellent.

Water absorption ratio:
After applying the water absorption preventive material, the specimens and non-coated specimens cured in a constant temperature and humidity chamber at a temperature of 20 ° C. and a relative humidity of 65% RH for 7 days are immersed in water with the coating surface down (immersion depth). 5 mm), and after 1 day and 20 days, the excess water was wiped off with a dry cloth, the weight (g) was measured, and the water absorption ratio was calculated by the following equation. The results are shown in Table 1. In addition, when a water absorption ratio is 0.1 or less, it can be judged that it is excellent in water absorption prevention property.

  As is apparent from Table 1, the water absorption preventing material obtained in each example is stable with respect to the phase separation of the emulsion and does not phase separate for 6 months. In addition, the specimen coated with the water absorption preventing material obtained in each example has very good water repellency, has a high water repellency expression rate, and can maintain its water repellency and water absorption preventing property over a long period of time. Recognize. Although the details of this mechanism are unknown, it is thought to be due to the interaction between the water-soluble water repellent and the water repellent layer formed by the organosilicon compound emulsion. In Comparative Example 2 using a fluorine-based aqueous emulsion water repellent, the water repellency is not sufficiently expressed. This is presumably because the emulsifier in the fluorine-based aqueous emulsion water repellent inhibits the water repellency of the water repellent layer formed by the organosilicon compound emulsion.

  Although the water absorption preventing material of the present invention is a water-based water absorption preventing material, it imparts very excellent water repellency to the surface of civil engineering and building base materials such as cement products, while suppressing the occurrence of dirt and wrinkles, By penetrating deeply into the base material to form a hydrophobic (water repellent) layer, the base material can be provided with excellent water absorption prevention properties, and the deterioration phenomenon can be suppressed for a long term. Thus, the water absorption preventing material of the present invention is extremely useful in the civil engineering / architectural field.

Claims (4)

  A water absorption preventing material comprising an organic silicon compound emulsion and a water-soluble water repellent.   The organosilicon compound emulsion is an emulsion containing (a) an alkylalkoxysilane and (b) an alkylalkoxysiloxane, wherein the ratio of (a) and (b) is 1: 0.05 to 0.4 by weight, and The water absorption preventive material according to claim 1, wherein the total amount of (a) and (b) is 1 to 80% by weight of the total amount of the emulsion.   The water absorption preventing material according to claim 1 or 2, wherein the water-soluble water repellent is a composition containing a fluoroalkyl group-containing organopolysiloxane.   The water absorption preventive material according to any one of claims 1 to 3, wherein the water-soluble water repellent is 0.01 to 30% by weight based on the total amount of the organosilicon compound emulsion.